Factors influencing RYGB anaesthesia-related complications

Post-operative nausea and vomiting (PONV) are the most common anaesthesia-related complication following Roux-en-Y gastric bypass, although this procedure has few anaesthetic complications, according to researchers University Hospital Zurich, Switzerland. The study authors found that factors affecting PONV had a strong impact on the overall predictors of anaesthesia complication. For example, PONV was more common in younger and female patients.

The paper, ‘Perioperative surgery- and anaesthesia-related risks of laparoscopic Roux-en-Y gastric bypass - a single centre, retrospective data analysis’, published in BMC Anesthesiology, assessed the anaesthesia and surgery-related perioperative risk of obese patients after RYGB surgery at University Hospital Zurich between 2006 and 2013.

The researchers recorded the length of hospital stay, the number of days in the intensive care unit (ICU) and the numbers of hospital re-admissions during the first 30 post-operative days, from 711 (72% female, median age 40 years) patients with a median BMI45 (41–49) who underwent a primary standard laparoscopic RYGB between January 2006 and December 2013. Using the ASA classification (estimated anaesthesia-related risk), 416 patients (60%) patients were classified as ASA II, 278 (40%) as ASA III, five patients (1%) as ASA IV. The median length of surgery was 145 (120–173) minutes and median anaesthesia duration was 270 (235–310) minutes with desflurane being the predominantly used anaesthetic in 89% of the patients.

Outcomes

Overall, 37% of patients experienced anaesthesia-related complications, with 34% presenting with PONV. Patients older than 35 years had a lower incidence of PONV (43 vs 29% p<0.001), PONV was more frequent in females (38 vs 23%, p< 0.001) and less frequent when volatile anaesthesia was used (p < 0.001). The authors reported that some patients suffered from several complications, explaining why the sum of the different subgroups exceeds the overall number of patients with complications.

There were no surgical complications reported in 66% of the patients. Of the remaining patients, 5% had a complication grade I, 16% grade II, 6% grade IIIa and 7% grade IIIb. There were no patients with grade IVa or IVb complications and no mortality (complication grade V). Patients with Clavien-Dindo complications grade IIIb were surgically re-explored due to: infections in 4% (n=27), anastomotic leak in 1% (n=8), haematoma evacuation or active bleeding in 1% (n=7), incisional hernia in 1% (n=4).

A multivariate analysis on the impact of age, duration of surgery, BMI, T2DM, the type of anaesthesia and the use of catecholamines on the occurrence of major surgical complications (defined according Clavien-Dindo grade IIIb and higher) showe, that a lower BMI was associated with higher incidence of major surgical complications (15 vs 6%, p=0.04) and that a procedure lasting longer than 170 min was associated with more complications (12 vs. 5%, p=0.01) (Table 1).

“Our findings suggest that bariatric surgery is performed with low surgery- and anaesthesia-related complication rates,” the authors concluded. “The majority of surgical complications were low grade (IIIA or less). A higher incidence of severe complications was observed in patients with a longer surgery and with a lower BMI. Patients with T2DM have a higher risk of infectious complications.”